Pattern formation method, block copolymer, and pattern formation material

ABSTRACT

According to one embodiment, a pattern formation method is disclosed. The method includes a preparation process, a block copolymer layer formation process, and a contact process. The preparation process includes preparing a pattern formation material including a block copolymer including a first block and a second block. The first block includes a first main chain and a plurality of first side chains. At least one of the first side chains includes a plurality of carbonyl groups. The block copolymer layer formation process includes forming a block copolymer layer on a first member. The block copolymer layer includes the pattern formation material and includes a first region and a second region. The first region includes the first block. The second region includes the second block. The contact process includes causing the block copolymer layer to contact a metal compound including a metallic element.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority fromJapanese Patent Application No. 2017-234631, filed on Dec. 6, 2017; theentire contents of which are incorporated herein by reference.

FIELD

Embodiments described herein relate generally to a pattern formationmethod, a block copolymer, and a pattern formation material.

BACKGROUND

For example, there is a method for forming a pattern by directedself-assembly (DSA) of a block copolymer, etc. It is desirable toincrease the pattern precision of the pattern formation method and thepattern formation material.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view illustrating a pattern formation materialused in a pattern formation method according to a first embodiment;

FIG. 2A to FIG. 2F are schematic cross-sectional views illustrating thepattern formation method according to the first embodiment; and

FIG. 3A and FIG. 3B are microscope photographs illustrating theexperimental results.

DETAILED DESCRIPTION

According to one embodiment, a pattern formation method is disclosed.The method includes a preparation process, a block copolymer layerformation process, and a contact process. The preparation processincludes preparing a pattern formation material including a blockcopolymer including a first block and a second block. The first blockincludes a first main chain and a plurality of first side chains. Atleast one of the first side chains includes a plurality of carbonylgroups. The block copolymer layer formation process includes forming ablock copolymer layer on a first member. The block copolymer layerincludes the pattern formation material and includes a first region anda second region. The first region includes the first block. The secondregion includes the second block. The contact process includes causingthe block copolymer layer to contact a metal compound including ametallic element.

According to another embodiment, a block copolymer includes a firstblock, and a second block. The first block includes a first main chainand a plurality of first side chains. At least one of the first sidechains includes a plurality of carbonyl groups. A number of carbon atomsincluded in the at least one of the first side chains is not less than 3but less than 7. A number of oxygen atoms included in the at least oneof the first side chains is not less than 2 but less than 5. A terminalof the at least one of the first side chains is a hydrocarbon.

According to another embodiment, a pattern formation material includesthe block copolymer described above, and a solvent.

Various embodiments will be described hereinafter with reference to theaccompanying drawings.

The drawings are schematic and conceptual; and the relationships betweenthe thickness and width of portions, the proportions of sizes amongportions, etc., are not necessarily the same as the actual valuesthereof. Further, the dimensions and proportions may be illustrateddifferently among drawings, even for identical portions.

In the specification and drawings, components similar to those describedor illustrated in a drawing thereinabove are marked with like referencenumerals, and a detailed description is omitted as appropriate.

First Embodiment

FIG. 1 is a schematic view illustrating a pattern formation materialused in a pattern formation method according to a first embodiment.

As shown in FIG. 1, the pattern formation material 120 includes a blockcopolymer 20. The pattern formation material 120 may further include asolvent. Examples of the solvent are described below.

The block copolymer 20 includes a first block 21 and a second block 22.In the example, the block copolymer 20 is a diblock copolymer. Thenumber of types of blocks included in the block copolymer 20 may bethree or more. The first block 21 is different from the second block 22.The first block 21 includes, for example, a carbonyl group. On the otherhand, in one example, the second block 22 does not include, for example,a carbonyl group.

The first block 21 includes a first main chain 25 and multiple firstside chains 26 (side chains 26A, 26B, 26C, 26D, etc.). In the firstblock 21, at least one of the multiple first side chains 26 (e.g., theside chain 26A) includes multiple carbonyl groups.

The first block 21 includes, for example, at least one of PAcAA(polyacetonyl acrylate) or PAcMA (polyacetonyl methacrylate).

For example, the density of the carbonyl group with respect to themolecular weight is high for PAcAA and PAcMA. In the case where PAcAA orPAcMA is included in the first block 21, the concentration of a metallicelement introduced to a first region R1 in a contact process describedbelow easily becomes high.

On the other hand, the second block 22 includes, for example, a secondmain chain 27 and multiple second side chains 28 (e.g., side chains 28A,28B, 28C, 28D, etc.). For example, the multiple second side chains 28 donot include multiple carbonyl groups. For example, at least one of themultiple second side chains 28 does not include a carbonyl group. Thenumber of carbonyl groups included in at least one of the multiplesecond side chains 28 may be 1. At least one of the multiple second sidechains 28 may include, for example, at least one selected from the groupconsisting of benzene, naphthalene, and methyl. For example, the secondblock 22 may include the second main chain 27 and may not include a sidechain (e.g., the side chains 28A, 28B, 28C, 28D, etc.). The second mainchain 27 may include, for example, at least one selected from the groupconsisting of a double bond and an ether bond. The second block 22includes, for example, at least one selected from the group consistingof PS (polystyrene), PVN (polyvinyl naphthalene), polyisoprene, andpolyethylene glycol.

The surface energies of the first block 21 and the second block 22 aredifferent from each other. Therefore, by providing a layer of the blockcopolymer 20 including these blocks on an appropriate neutralizinglayer, phase separation of these blocks occurs by for example, directedself-assembly. For example, lamellae that include the first block 21 andlamellae that include the second block 22 are arranged perpendicularlyon the neutralizing layer. The surface energy of the appropriateneutralizing layer is between the surface energies of these blocks.

An example of a pattern formation method using such a pattern formationmaterial will now be described. A graphoepitaxy guide is used in thefollowing pattern formation method. A chemoepitaxy guide may be used inthe embodiment.

FIG. 2A to FIG. 2F are schematic cross-sectional views illustrating thepattern formation method according to the first embodiment.

As shown in FIG. 2A, a structure body 65 is formed on a substrate 60 s.The structure body 65 functions as a graphoepitaxy guide. The structurebody 65 includes a projection 65 p and a recess 65 d. The structure body65 includes, for example, a thermocurable resin or a photocurable resin.For example, the structure body 65 can be formed by photolithography andetching. For example, the structure body 65 also can be formed byimprinting.

As shown in FIG. 2B, a first layer 10F is formed on the structure body65. The first layer 10F is provided on the surface (the top surface andthe side surface) of the projection 65 p and on the surface of therecess 65 d. For example, the first layer 10F covers these surfaces. Thesurface energy of the first layer 10F is larger than the surface energyof the second block 22 (e.g., PS) and smaller than the surface energy ofthe first block 21 (e.g., PAcMA). For example, the first layer 10Ffunctions as a neutralization film.

In the embodiment, the first layer 10F is provided as necessary. Forexample, the first layer 10F may be omitted in the case where thesurface energy of the structure body 65 is appropriate. A first member60 includes, for example, the structure body 65. The first member 60 mayinclude, for example, the substrate 60 s. The first member 60 mayinclude the first layer 10F.

For example, the first member 60 spreads along the X-Y plane. Adirection perpendicular to the X-Y plane is taken as a Z-axis direction.The position in the Z-axis direction of the top portion of theprojection 65 p is different from the position in the Z-axis directionof the recess 65 d.

As shown in FIG. 2C, a block copolymer layer 20F is formed on the firstmember 60. The block copolymer layer 20F includes the block copolymer 20(the first block 21 recited above and the second block 22 recitedabove).

For example, phase separation of the first block 21 and the second block22 is caused by heat treatment, etc. Thereby, a first region R1 thatincludes the first block 21 and a second region R2 that includes thesecond block 22 are formed. The first region R1 and the second region R2each are oriented perpendicularly to the major surface of the firstmember 60. For example, the direction from the first region R1 towardthe second region R2 is along the first member 60. The direction fromthe first region R1 toward the second region R2 is aligned with the X-Yplane. Thus, a block copolymer layer formation process is performed.

In the example, the first region R1 is positioned on the projection 65p. A set of one first region R1 and one second region R2 is arrangedbetween two projections 65 p. The pitch of the set of the one firstregion R1 and the one second region R2 is smaller than the pitch of theprojections 65 p.

As shown in FIG. 2D, the block copolymer layer 20F is caused to contacta metal compound 30 including a metallic element 31. Thus, a contactprocess is performed.

The metal compound 30 may include, for example, a metal complexincluding the metallic element 31. The metallic element 31 may include,for example, at least one selected from the group consisting ofaluminum, zinc, titanium, and tungsten. The metal compound 30 mayinclude, for example, trimethyl aluminum (TMA).

The contact process includes, for example, causing the block copolymerlayer 20F to contact at least one of a liquid including the metalcompound 30 or a gas including the metal compound 30. Thereby, the metalcompound 30 is introduced to at least a portion of the block copolymerlayer 20F. For example, at least a portion of the block copolymer layer20F is metallized. For example, the metal compound 30 is diffused in thefirst region R1. At this time, the metal compound 30 may be diffused inthe second region R2.

The structure of the first block 21 of the first region R1 is differentfrom that of the second block 22 of the second region R2. For example,the polarity of the first region R1 is higher than the polarity of thesecond region R2. For example, the concentration of the metal compound30 introduced to the first region R1 may be higher than theconcentration of the metal compound 30 introduced to the second regionR2. The contact process includes, for example, introducing the metalcompound 30 to the first region R1.

As described above, the first block 21 of the first region R1 includesthe multiple first side chains 26. At least one of the multiple firstside chains 26 (e.g., the side chain 26A) includes multiple carbonylgroups. As described below, the metallic element 31 that is included inthe metal compound 30 is easily adsorbed to a carbonyl group. The firstside chain 26 of the first block 21 includes multiple carbonyl groups.Therefore, the concentration of the metallic element 31 easily becomeshigh compared to that of polymethyl methacrylate (PMMA) or the like ofwhich the number of carbonyl groups included in the side chain is 1.

On the other hand, the concentration of the metallic element 31 is lowin the second region R2 including the second block 22 that does notinclude a carbonyl group.

After the contact process, the concentration of the metallic element 31in the second region R2 is lower than the concentration of the metallicelement 31 in the first region R1.

After the contact process recited above as shown in FIG. 2E, treatmentof the block copolymer layer 20F in an atmosphere 62 including at leastone selected from the group consisting of water, oxygen including aplasma state, and ozone is performed. The treatment process is, forexample, an oxidation process.

Thereby, after the processing process, the first region R1 includes anoxide 32 including the metallic element 31. On the other hand, the oxide32 that includes the metallic element 31 is substantially not formed inthe second region R2.

The oxide 32 that includes the metallic element 31 includes, forexample, at least one selected from the group consisting of aluminumoxide, zinc oxide, titanium oxide, and tungsten oxide.

Due to such an oxide 32, the etching resistance of the first region R1is higher than the etching resistance of the second region R2. Theetching rate of the first region R1 is lower than the etching rate ofthe second region R2.

After the processing process recited above as shown in FIG. 2F, thesecond region R2 is removed. As described above, the etching rate of thefirst region R1 is lower than the etching rate of the second region R2.Therefore, the first region R1 remains.

Further, at least a portion of the portion of the first member 60 notoverlapping the first region R1 is removed. As described below, by usingan appropriate material as the first layer 10F, the concentration of themetallic element 31 (or the oxide 32) included in the first layer 10Fcan be low. The removal of the portion of the first layer 10F notoverlapping the first region R1 is easy.

The removal (a first removal) of the second region R2 may be performedcontinuously with the removal (a second removal) of the at least aportion of the portion of the first member 60 not overlapping the firstregion R1. These removals are performed by, for example, RIE (ReactiveIon Etching), etc. The etching conditions of the first removal may bedifferent from the etching conditions of the second removal.

In the embodiment, the oxide 32 substantially is not formed in thesecond region R2 that substantially does not include a carbonyl group. Ahigh etching rate can be maintained in the second region R2. On theother hand, a low etching rate is obtained in the first region R1including the carbonyl groups. Therefore, the selectivity (thedifference of the etching rates, e.g., the etching contrast) between thefirst region R1 and the second region R2 can be large. According to theembodiment, a pattern formation method in which the pattern precisioncan be increased.

In the contact process recited above, the metal compound 30 thatincludes the metallic element 31 contacts the block copolymer layer 20F.It was found that the metal compound 30 adsorbs (which may includebonding) to the carbonyl groups at this time. For example, fromcalculations using a quantum chemical calculation program (Gaussian,etc.), it was found that the metallic element 31 (e.g., Al) of the metalcompound 30 is adsorbed (bonded) to a carbonyl group more easily than toa hydrocarbon or an ether group. In the case where the concentration ofthe carbonyl group included in the polymer is high, the concentration ofthe metallic element 31 of the metal compound 30 adsorbed to the polymeris high.

After the contact process in the embodiment, for example, the metallicelement 31 is adsorbed (which may include bonding) to the carbonylgroups.

The metallic element 31 (e.g., Al) of the metal compound 30 exists at ahigh concentration in the first region. R1 including the carbonylgroups. In the embodiment, at least one of the first side chain 26 ofthe first block 21 includes multiple carbonyl groups. Therefore, theconcentration of the metallic element 31 in the first region R1 is highcompared to the case of PMMA or the like of which the number of carbonylgroups included in the side chain is 1.

On the other hand, the concentration of the metallic element 31 in thesecond region R2 is low. Thereby, the etching can be performedeffectively using the first region R1 as a mask.

An example of experimental results relating to the etching resistance ofthe polymer film after the processing process recited above (e.g., theoxidation process) will now be described.

In the experiment, a film of a material including a polymer including acarbonyl group is formed on a silicon substrate. A first sample includesPAcMA. A second sample includes PMMA. In the experiment, instead of ablock copolymer, the first block 21 is provided and the second block 22is not provided. After the formation of the film of these samples,treatment with TMA (a contact process for the metal compound 30including the metallic element 31) and treatment (a processing process,e.g., an oxidation process) in the atmosphere 62 including water areperformed. Subsequently, RIE processing (etching) using a gas includingoxygen plasma is performed. The film after the etching is observed by ascanning electron microscope (SEM).

FIG. 3A and FIG. 3B are microscope photographs illustrating theexperimental results.

FIG. 3A corresponds to the first sample SP01 (PAcMA). FIG. 3Bcorresponds to the second sample SP02 (PMMA).

As shown in FIG. 3B, large holes (the dark regions inside thephotograph) are observed for the film after the etching of the secondsample SP02. Conversely, for the first sample SP01 as shown in FIG. 3A,holes are substantially not observed (or the sizes of the holes aresmall).

It can be seen from FIG. 3A and FIG. 3B that the etching resistanceimproves when the side chain of the polymer includes the multiplecarbonyl groups. It is considered that the improvement of the etchingresistance has a relationship with the concentration of the metallicelement 31 (the concentration of the oxide 32) becoming high due to theside chain of the polymer including the multiple carbonyl groups.

In the embodiment, examples of the first side chain 26 (e.g., the sidechain 26A) including the multiple carbonyl groups can be represented by,for example, the following first to third chemical formulas.

In the embodiment, examples of the first block 21 can be represented by,for example, the following fourth to sixth chemical formulas.

In the fourth to sixth chemical formulas, R1 to R3 are hydrogen atoms ormethyl groups. R1 to R3 may be the same or different from each other. n1to n3 are the numbers of repetitions and may be the same or differentfrom each other. For example, n1 to n3 are not less than 50 and not morethan 10,000.

In the embodiment, the first block 21 includes, for example, at leastone selected from the group consisting of an acrylic acid esterstructure and a methacrylic acid ester structure. The first block 21 ismade of, for example, a repetition of a monomer including at least oneselected from the group consisting of an acrylic acid ester structureand a methacrylic acid ester structure.

The first block 21 includes, for example, at least one selected from thegroup consisting of acetonyl acrylic acid ester and acetonyl methacrylicacid ester. The first block 21 includes, for example, at least oneselected from the group consisting of a polymer of acetonyl acrylic acidester and a polymer of acetonyl methacrylic acid ester. The first block21 includes, for example, at least one selected from the groupconsisting of polyacetonyl acrylic acid ester (PAcAA) and polyacetonylmethacrylic acid ester (PAcMA). For example, PAcAA and PAcMA can besynthesized relatively easily.

The ratio (C2/C1) of a concentration C2 of the carbonyl group includedin the second block 22 to a concentration C1 of the carbonyl groupincluded in the first block 21 may be, for example, not less than 0 andnot more than 0.5. C2/C1 may be, for example, not less than 0 and notmore than 0.1. C2/C1 may be, for example, not less than 0 and not morethan 0.01. C2/C1 may be, for example, not less than 0 and not more than0.001.

In the embodiment, examples of the second block 22 can be representedby, for example, the following seventh to eleventh chemical formulas.

In the seventh to eleventh chemical formulas, R4 is a hydrogen atom or amethyl group. n4 to n8 are the numbers of repetitions and may be thesame or different from each other. For example, n4 to n8 are not lessthan 50 and not more than 10,000.

As described above, the pattern formation material 120 according to theembodiment may include a solvent. The solvent includes, for example, atleast one selected from the group consisting of propylene glycolmonomethyl ether acetate (PGMEA), propylene glycol monomethyl ether(PGME), anisole, toluene, ethyl lactate, and tetrahydrofuran (THF).

The concentration of the block copolymer 20 of the pattern formationmaterial 120 is, for example, not less than 0.01 weight % and not morethan 50 weight %.

By setting the solvent and the concentration appropriately, a uniformfilm that includes the pattern formation material can be formed easily.

An example of the first layer 10F will now be described.

In the embodiment, for example, the material (a first layer formationmaterial) of the first layer 10F substantially does not include acarbonyl group. Therefore, the concentration of the metallic element 31in the first layer 10F is low.

For example, the material (the first layer formation material) of thefirst layer 10F includes, for example, a polymer including a firstmonomer including carbon, hydrogen, and a first group. The first groupincludes, for example, at least one of a vinyl group, a hydroxy group,and a first element. The first element includes at least one selectedfrom the group consisting of fluorine, chlorine, and bromine. The firstgroup includes, for example, at least one selected from the groupconsisting of vinyl alcohol, hydroxystyrene, and vinyl chloride.

For example, after the contact process (the contact with the metalcompound 30), the concentration of the metallic element 31 in the firstlayer 10F is lower than the concentration of the metallic element 31 inthe first region R1. After the oxidation process (e.g., the processingin the atmosphere 62 including at least one selected from the groupconsisting of water, oxygen including a plasma state, and ozone), theoxide 32 that includes the metallic element 31 is substantially notformed in the first layer 10F. The etching rate of the first region R1is lower than the etching rate of the first layer 10F.

In the process shown in FIG. 2F, the portion of the first layer 10F notoverlapping the first region R1 is removed easily. The etching rate ofthe first region R1 is lower than the etching rate of the first layer10F. For example, the oxide 32 is not formed in the first layer 10F.Therefore, a high etching rate can be maintained for the first layer10F. The selectivity between the first region R1 and the first layer 10Fcan be large. A pattern formation method in which the pattern precisioncan be increased.

For example, the surface energy of the polymer included in the firstlayer formation material of the first layer 10F is between the surfaceenergies of the multiple blocks included in the block copolymer.

Examples of the polymer included in the first layer formation materialcan be represented by, for example, the following twelfth to sixteenthchemical formulas.

In the twelfth to sixteenth chemical formulas, R5 is a hydrogen atom ora methyl group. n9 to n13 are the numbers of repetitions and may be thesame or different from each other. For example, n9 to n13 are not lessthan 10 and not more than 10,000.

The polymer that is included in the first layer formation material doesnot include a carbonyl group. Or, in the case where the polymer that isincluded in the first layer formation material includes a carbonylgroup, the concentration of the carbonyl group of the polymer includedin the first layer formation material is, for example, 0.0005 mol/g orless. The concentration of the carbonyl group of the polymer included inthe first layer formation material may be 0.00005 mol/g or less. Theconcentration of the carbonyl group of the polymer included in the firstlayer formation material may be 0.000005 mol/g or less. For example, theconcentration of the metallic element 31 in the first layer 10F afterthe contact process can be low.

In the process illustrated in FIG. 2B (the formation of the first layer10F), for example, a solution of the first layer formation material iscoated onto the surface of the projection 65 p. The method for coatingincludes, for example, any method such as inkjet, dip coating, barcoating, spin coating, etc. Heat treatment is performed as necessary.Thereby, the first layer 10F is formed.

Second Embodiment

The second embodiment relates to a block copolymer. The block copolymer20 (referring to FIG. 1) includes the first block 21 and the secondblock 22. The block copolymer 20 is, for example, a diblock copolymer.The number of types of blocks included in the block copolymer 20 may bethree or more. The first block 21 is different from the second block 22.The first block 21 includes, for example, a carbonyl group. On the otherhand, in one example, for example, the second block 22 does not includea carbonyl group.

The first block 21 includes the first main chain 25 and the multiplefirst side chains 26 (e.g., the side chains 26A, 26B, 26C, 26D, etc.).

At least one of the multiple first side chains 26 of the first block 21(e.g., the side chain 26A) includes multiple carbonyl groups. The numberof carbon atoms included in the at least one of the multiple first sidechains 26 (e.g., the side chain 26A) is not less than 3 but less than 7.The number of oxygen atoms included in the at least one of the multiplefirst side chains 26 (e.g., the side chain 26A) is not less than 2 butless than 5. The terminal of the at least one of the multiple first sidechains 26 (e.g., the side chain 26A) is a hydrocarbon. In the at leastone of the multiple first side chains 26 (e.g., the side chain 26A), thefurthest carbon atom from the first main chain 25 is bonded to hydrogenatoms.

Because at least one of the multiple first side chains 26 includes themultiple carbonyl groups, for example, the concentration of the metallicelement 31 can be set high after the contact process recited above. Ablock copolymer and a pattern formation material can be provided inwhich the pattern precision is increased.

In the case where the number of carbon atoms is 7 or more, for example,the storage stability of the block copolymer becomes low. It isconsidered that the glass transition temperature of the phase formed bythe first block 21 is below room temperature in the case where thenumber of carbon atoms included in at least one of the multiple firstside chains 26 of the first block 21 (e.g., the side chain 26A) is 7 ormore.

As a result, the phase is constantly in an environment that is above theglass transition temperature; and side reactions such as crosslinking,etc., occur easily inside the phase. Because the multiple carbonylgroups are included in the side chain 26A, the minimum value of thenumber of carbon atoms included in the side chain 26A is 2.

In the case where the number of oxygen atoms is 5 or more, for example,the storage stability of the block copolymer becomes low. It isconsidered that the glass transition temperature of the phase formed bythe first block 21 is below room temperature in the case where thenumber of oxygen atoms included in at least one of the multiple firstside chains 26 of the first block 21 (e.g., the side chain 26A) is 5 ormore. As a result, the phase is constantly in an environment that isabove the glass transition temperature; and side reactions such ascrosslinking, etc., occur easily inside the phase. Because the multiplecarbonyl groups are included in the side chain 26A, the minimum value ofthe number of oxygen atoms included in the side chain 26A is 2.

High stability is obtained when the terminal is a hydrocarbon. Forexample, in the case where the terminal is a carboxy group, for example,the polarity may increase and may become insoluble to the desiredsolvent.

The first block 21 includes, for example, at least one selected from thegroup consisting of an acrylic acid ester structure and a methacrylicacid ester structure. The first block 21 is made of, for example, apolymer of a monomer including at least one selected from the groupconsisting of an acrylic acid ester structure and a methacrylic acidester structure.

The first block 21 includes, for example, at least one selected from thegroup consisting of acetonyl acrylic acid ester and acetonyl methacrylicacid ester. The first block 21 includes, for example, at least oneselected from the group consisting of a polymer of acetonyl acrylic acidester and a polymer of acetonyl methacrylic acid ester. The first block21 includes, for example, at least one selected from the groupconsisting of PAcAA and PAcMA.

For example, PAcAA and PAcMA can be synthesized relatively easily. Thedensity of the carbonyl group with respect to the molecular weight ishigh for PAcAA and PAcMA.

The second block 22 includes, for example, the second main chain 27 andthe multiple second side chains 28 (e.g., the side chains 28A, 28B, 28C,28D, etc.). For example, the multiple second side chains 28 do notinclude multiple carbonyl groups. For example, at least one of themultiple second side chains 28 does not include a carbonyl group. Thenumber of carbonyl groups included in at least one of the multiplesecond side chains 28 may be 1. At least one of the multiple second sidechains may include, for example, at least one selected from the groupconsisting of benzene, naphthalene, and methyl. For example, the secondblock 22 may include the second main chain 27 and may not include a sidechain (e.g., the side chains 28A, 28B, 28C, 28D, etc.). The second mainchain 27 may include, for example, at least one selected from the groupconsisting of a double bond and an ether bond. The second block 22includes, for example, at least one selected from the group consistingof PS (polystyrene), PVN (polyvinyl naphthalene), polyisoprene, andpolyethylene glycol.

The ratio (C2/C1) of the concentration C2 of the carbonyl group includedin the second block 22 to the concentration C1 of the carbonyl groupincluded in the first block 21 is, for example, not less than 0 and notmore than 0.5. For example, C2/C1 may be not less than 0 and not morethan 0.1. For example, C2/C1 may be not less than 0 and not more than0.01. For example, C2/C1 may be not less than 0 and not more than 0.001.

For example, the block copolymer according to the embodiment ismanufactured by the following method.

Copper bromide, acetonyl acrylate (AcAA), andN-propyl-2-pyridylmethanimine are added to toluene in a flask; thereaction vessel is deoxidized and is heated to 90° C. After the heating,2-ethyl bromoisobutyrate is added to start the polymerization. Theentire reaction is performed in a nitrogen atmosphere. After 24 hours,styrene is added to the reaction solution; and the reaction is performedfor another 24 hours. After the reaction, the flask is opened to air andslowly cooled. The toluene is removed in vacuo; and the concentratedliquid is reprecipitated into a large excess of methanol. A solid isfiltered off; and the desired diblock copolymer is obtained.

For example, polyacetonyl acrylate (PAcAA), which is acetonyl acrylicacid ester polymerized as a homopolymer and is used to form the materialof the first block, is a viscous body in a rubber state at roomtemperature; and the handling properties of the PAcAA homopolymer arepoor. Conversely, the block copolymer obtained by combining PAcAA withthe second block (e.g., PS) is a powder. The handling properties of thisblock copolymer are good. Thus, the handling properties of the polymercan be improved by using a block copolymer.

Third Embodiment

A third embodiment relates to a pattern formation material. The patternformation material includes the block copolymer 20 (referring to FIG. 1)and a solvent.

The solvent includes, for example, at least one selected from the groupconsisting of propylene glycol monomethyl ether acetate (PGMEA),propylene glycol monomethyl ether (PGME), anisole, toluene, ethyllactate, and tetrahydrofuran (THF).

The concentration of the block copolymer 20 of the pattern formationmaterial is, for example, not less than 0.01 weight % and not more than50 weight %.

By setting the solvent and the concentration appropriately, a uniformfilm that includes the pattern formation material can be formed easily.

The embodiments include, for example, the following configurations(e.g., technological proposals).

Configuration 1

A pattern formation method, comprising:

a preparation process of preparing a pattern formation materialincluding a block copolymer including a first block and a second block,the first block including a first main chain and multiple first sidechains, at least one of the multiple first side chains includingmultiple carbonyl groups;

a block copolymer layer formation process of forming a block copolymerlayer on a first member, the block copolymer layer including the patternformation material and including a first region and a second region, thefirst region including the first block, the second region including thesecond block; and

a contact process of causing the block copolymer layer to contact ametal compound including a metallic element.

Configuration 2

The pattern formation method according to Configuration 1, wherein theblock copolymer layer formation process includes phase separation of thefirst block and the second block.

Configuration 3

The pattern formation method according to Configuration 1 or 2, whereina direction from the first region toward the second region is along thefirst member.

Configuration 4

The pattern formation method according to any one of Configurations 1 to3, wherein the first block includes at least one selected from the groupconsisting of an acrylic acid ester structure and a methacrylic acidester structure.

Configuration 5

The pattern formation method according to any one of Configurations 1 to3, wherein the first block includes at least one selected from the groupconsisting of acetonyl acrylic acid ester and acetonyl methacrylic acidester.

Configuration 6

The pattern formation method according to any one of Configurations 1 to5, wherein the second block includes a second main chain and multiplesecond side chains, the multiple second side chains not includingmultiple carbonyl groups.

Configuration 7

The pattern formation method according to any one of Configurations 1 to5, wherein

the second block includes a second main chain and multiple second sidechains, and

at least one of the multiple second side chains includes at least oneselected from the group consisting of benzene, naphthalene, and methyl.

Configuration 8

The pattern formation method according to any one of Configurations 1 to5, wherein the second block includes a second main chain, and the secondmain chain includes at least one selected from the group consisting of adouble bond and an ether bond.

Configuration 9

The pattern formation method according to any one of Configurations 1 to8, wherein

the second block does not include a carbonyl group, or

the second block includes a carbonyl group, and a ratio of aconcentration of the carbonyl group included in the second block to aconcentration of the carbonyl group included in the first block is 0.5or less.

Configuration 10

The pattern formation method according to any one of Configurations 1 to9, wherein the contact process includes causing the block copolymerlayer to contact at least one of a liquid including the metal compoundand a gas including the metal compound.

Configuration 11

The pattern formation method according to any one of Configurations 1 to10, wherein the metallic element includes at least one selected from thegroup consisting of aluminum, zinc, titanium, and tungsten.

Configuration 12

The pattern formation method according to any one of Configurations 1 to11, including removing at least a portion of the second region andremoving at least a portion of the first member after the contactprocess, the at least a portion of the first member not overlapping thefirst region.

Configuration 13

A block copolymer, comprising:

a first block; and

a second block,

the first block including a first main chain and multiple first sidechains,

at least one of the multiple first side chains including multiplecarbonyl groups,

a number of carbon atoms included in the at least one of the multiplefirst side chains being not less than 3 but less than 7,

a number of oxygen atoms included in the at least one of the multiplefirst side chains being not less than 2 but less than 5,

a terminal of the at least one of the multiple first side chains being ahydrocarbon.

Configuration 14

The block copolymer according to Configuration 13, wherein the firstblock includes at least one selected from the group consisting of anacrylic acid ester structure and a methacrylic acid ester structure.

Configuration 15

The block copolymer according to Configuration 13, wherein the firstblock includes at least one selected from the group consisting ofacetonyl acrylic acid ester and acetonyl methacrylic acid ester.

Configuration 16

The block copolymer according to any one of Configurations 13 to 15,wherein the second block includes a second main chain and multiplesecond side chains, and the multiple second side chains do not includemultiple carbonyl groups.

Configuration 17

The block copolymer according to any one of Configurations 13 to 15,wherein

the second block includes a second main chain and multiple second sidechains, and

at least one of the multiple second side chains includes at least oneselected from the group consisting of benzene, naphthalene, and methyl.

Configuration 18

The block copolymer according to any one of Configurations 13 to 15,wherein

the second block includes a second main chain, and

the second main chain includes at least one selected from the groupconsisting of a double bond and an ether bond.

Configuration 19

The block copolymer according to any one of Configurations 13 to 18,wherein

the second block does not include a carbonyl group, or

the second block includes a carbonyl group, and a ratio of aconcentration of the carbonyl group included in the second block to aconcentration of the carbonyl group included in the first block is 0.5or less.

Configuration 20

A pattern formation material, comprising:

the block copolymer according to any one of Configurations 13 to 19; anda solvent.

Configuration 21

The pattern formation material according to Configuration 20, whereinthe solvent includes at least one selected from the group consisting ofpropylene glycol monomethyl ether acetate, propylene glycol monomethylether, anisole, toluene, ethyl lactate, and tetrahydrofuran.

Configuration 22

The pattern formation material according to Configuration 20 or 21,wherein a concentration of the block copolymer of the pattern formationmaterial is not less than 0.01 weight % and not more than 50 weight %.

According to the embodiments, a pattern formation method, a blockcopolymer, and a pattern formation material can be provided in which thepattern precision can be increased.

Hereinabove, exemplary embodiments of the invention are described withreference to specific examples. However, the embodiments of theinvention are not limited to these specific examples. For example, oneskilled in the art may similarly practice the invention by appropriatelyselecting specific configurations of components used in patternformation method and pattern formation material such as polymers,monomers, block copolymers, etc., from known art. Such practice isincluded in the scope of the invention to the extent that similareffects thereto are obtained.

Further, any two or more components of the specific examples may becombined within the extent of technical feasibility and are included inthe scope of the invention to the extent that the purport of theinvention is included.

Moreover, all pattern formation methods, pattern formation materialspracticable by an appropriate design modification by one skilled in theart based on the pattern formation methods, the pattern formationmaterials described above as embodiments of the invention also arewithin the scope of the invention to the extent that the purport of theinvention is included.

Various other variations and modifications can be conceived by thoseskilled in the art within the spirit of the invention, and it isunderstood that such variations and modifications are also encompassedwithin the scope of the invention.

While certain embodiments have been described, these embodiments havebeen presented by way of example only, and are not intended to limit thescope of the inventions. Indeed, the novel embodiments described hereinmay be embodied in a variety of other forms; furthermore, variousomissions, substitutions and changes in the form of the embodimentsdescribed herein may be made without departing from the spirit of theinventions. The accompanying claims and their equivalents are intendedto cover such forms or modifications as would fall within the scope andspirit of the invention.

What is claimed is:
 1. A pattern formation method, comprising: apreparation process of preparing a pattern formation material includinga block copolymer including a first block and a second block, the firstblock including a first main chain and a plurality of first side chains,at least one of the first side chains including a plurality of carbonylgroups; a block copolymer layer formation process of forming a blockcopolymer layer on a first member, the block copolymer layer includingthe pattern formation material and including a first region and a secondregion, the first region including the first block, the second regionincluding the second block; and a contact process of causing the blockcopolymer layer to contact a metal compound including a metallicelement.
 2. The method according to claim 1, wherein the block copolymerlayer formation process includes phase separation of the first block andthe second block.
 3. The method according to claim 1, wherein adirection from the first region toward the second region is along thefirst member.
 4. The method according to claim 1, wherein the firstblock includes at least one selected from the group consisting of anacrylic acid ester structure and a methacrylic acid ester structure. 5.The method according to claim 1, wherein the first block includes atleast one selected from the group consisting of acetonyl acrylic acidester and acetonyl methacrylic acid ester.
 6. The method according toclaim 1, wherein the second block includes a second main chain and aplurality of second side chains, at least one of the second side chainnot including a plurality of carbonyl groups.
 7. The method according toclaim 1, wherein the second block includes a second main chain and aplurality of second side chains, and at least one of the second sidechains includes at least one selected from the group consisting ofbenzene, naphthalene, and methyl.
 8. The method according to claim 1,wherein the second block includes a second main chain, and the secondmain chain includes at least one selected from the group consisting of adouble bond and an ether bond.
 9. The method according to claim 1,wherein the second block does not include a carbonyl group, or thesecond block includes a carbonyl group, and a ratio of a concentrationof the carbonyl group included in the second block to a concentration ofthe carbonyl group included in the first block is 0.5 or less.
 10. Themethod according to claim 1, wherein the contact process includescausing the block copolymer layer to contact at least one of a liquidincluding the metal compound or a gas including the metal compound. 11.The method according to claim 1, wherein the metallic element includesat least one selected from the group consisting of aluminum, zinc,titanium, and tungsten.
 12. The method according to claim 1, includingremoving at least a portion of the second region and removing at least aportion of the first member after the contact process, the at least aportion of the first member not overlapping the first region.
 13. Ablock copolymer, comprising: a first block; and a second block, thefirst block including a first main chain and a plurality of first sidechains, at least one of the first side chains including a plurality ofcarbonyl groups, a number of carbon atoms included in the at least oneof the first side chains being not less than 3 but less than 7, a numberof oxygen atoms included in the at least one of the first side chainsbeing not less than 2 but less than 5, a terminal of the at least one ofthe first side chains being a hydrocarbon.
 14. The block copolymeraccording to claim 13, wherein the first block includes at least oneselected from the group consisting of an acrylic acid ester structureand a methacrylic acid ester structure.
 15. The block copolymeraccording to claim 13, wherein the first block includes at least oneselected from the group consisting of acetonyl acrylic acid ester andacetonyl methacrylic acid ester.
 16. The block copolymer according toclaim 13, wherein the second block includes a second main chain and aplurality of second side chains, and at least one of the second sidechains does not include a plurality of carbonyl groups.
 17. The blockcopolymer according to claim 13, wherein the second block includes asecond main chain and a plurality of second side chains, and at leastone of the second side chains includes at least one selected from thegroup consisting of benzene, naphthalene, and methyl.
 18. The blockcopolymer according to claim 13, wherein the second block includes asecond main chain, and the second main chain includes at least oneselected from the group consisting of a double bond and an ether bond.19. The block copolymer according to claim 13, wherein the second blockdoes not include a carbonyl group, or the second block includes acarbonyl group, and a ratio of a concentration of the carbonyl groupincluded in the second block to a concentration of the carbonyl groupincluded in the first block is 0.5 or less.
 20. A pattern formationmaterial, comprising: the block copolymer according to claim 13; and asolvent.